Cooking apparatuses for cooking or baking products are, for example, hot-air apparatuses, hot-air steamers, or baking ovens. They comprise a cooking chamber in which a food is prepared.
During the cooking process, so-called vapors are formed in the cooking chamber of the cooking apparatus. Vapors are predominantly in the form of steam and also consist of water vapor for the most part. In addition, they also contain oils and fats, which are present in the form of aerosols or else in liquid form. Other components may also be contained therein. The vapors are created during the cooking process through the vaporization of water that is contained in the foods; in addition, however, vapor that is fed into the cooking chamber of the apparatus also contributes to the creation of vapors. This feeding can be brought about either by way of an external steam generator or else also by direct vaporization of water inside of the hot cooking chamber. This water vapor is absolutely intentional and is important for certain aspects of the cooking process.
When fat-containing foods or fat-containing cooking products are cooked at high temperatures, the aforementioned oil and fat aerosols are additionally created.
In the case of so-called pressureless cooking apparatuses, a possibility must be created to allow excess vapors to escape. Otherwise, a pressure would build up within the cooking chamber. In order to prevent this, conventional cooking apparatuses often have an exhaust air opening from which the steam or the vapors can escape into the room air. In the case of high-performance apparatuses, this can lead to a strong accumulation of moisture and heat in the room air in the surroundings of the cooking apparatus and in the entire kitchen premises. Moreover, the room is also dirtied by the oil and fat aerosols. Hence, adequate ventilation and exhaust measures are required in rooms in which such cooking apparatuses having a relatively high capacity are installed. The rate of air exchange necessarily associated with these ventilation and exhaust measures results in a high energy requirement for the exhaust as well as additionally for the cooling and heating of the room air. For reasons of building engineering, in certain cases it is not even possible to install an exhaust unit, such as, for example, in the case of old buildings and/or for reasons of preservation of historic buildings or else in the case of so-called mobile catering.
In older grilling apparatuses, such as those known from DE 16 79 119 B, it is sufficient just to carry out a regular ventilation of the interior of the grill oven with fresh air and then to conduct away the smoke that is created. For this, it has already been suggested to pass the smoke through scrubbing or absorption equipment, which can be arranged in the lower part of the oven and can consist of a plurality of sheet metal partitions. In this way, the smoke will be forced through substances in order to deposit contaminants.
In order to reduce the problems entailed with ventilation and exhaust measures, an attempt is made to keep the created quantities of vapors as small as possible or else to reduce their discharge into the room air. Known for this purpose is the placement of water nozzles in the region of the exhaust opening or in the vapor channels by way of which the vapors are discharged into the room air. A baking oven having roughly this form of construction is described in DE 30 27 566 C2. These water nozzles can create a water mist, which results in the condensation of a portion of the vapors. This condensate is then carried to the drain of the cooking apparatus.
On account of the tight space situation within cooking apparatuses, such a condensation cannot be designed very effectively. This means that the water consumption is quite high in relation to the condensation capacity. Moreover, the relatively small cross sections of the nozzles that are used for creating the water mist become clogged relatively quickly with calcium deposits and dirt particles.
Proposed in DE 32 15 812 C2 is the condensation of the vapors in a mixing condenser, which is located within the cooking chamber and is designed to act at the same time as a water barrier like a type of siphon.
Described in DE 101 62 953 A1 is the creation of an additional condensation chamber beneath the cooking chamber, into which the vapors are introduced via a feed line. There, they are cooled with a water jet from an injector nozzle so that condensation can take place. After the condensation, the liquid vapors then run into the drain.
Known from DE 10 2006 034 081 A1 is another possibility of directing the vapors into a condensation device beneath the cooking chamber for condensing vapors and/or steam out of the cooking chamber, this device operating with a quenching device that injects water into the condensation device.
In order to bring about a more effective condensation of the vapors, therefore, external condensation devices are usually used. These are separate devices that are connected directly to the cooking apparatus. The vapors are carried to these condensation devices and the heats of vaporization of the vapors are then removed in these condensation devices by means of water injection or air cooling and accordingly condensed to the greatest extent possible. The greater volumes of these external condensation devices makes possible a markedly better condensation of the vapors. Undesired odor-causing substances and the fat and oil aerosols can be removed or eliminated by the water injection and also by additional filters.
Such a possibility is known, for instance, from DE 10 2005 050 483 A1, in which, after the heat treatment of the food, the vapors are carried into a separate device having a liquid bath in a container, with the carried gaseous vapors being passed through the liquid bath, which, moreover, is cooled.
A drawback of these concepts is that, in each case, an additional device is required, leading, on the one hand, to higher costs and, on the other hand, also to an appreciable increase in the volume of the overall apparatus made up of the cooking apparatus and the condensation device.
Therefore, the treatment of vapors in cooking apparatuses continues to remain a problem, because either their appropriate reduction is ineffective or else very costly and necessitates space-consuming designs.
The problem of the invention, therefore, is to propose a cooking apparatus that makes do without additional voluminous devices and, nonetheless, offers an effective reduction in the vapors discharged into the room.